2024-05-09 09:56:39

by Dev Jain

[permalink] [raw]
Subject: [PATCH] selftests/mm: hugetlb_madv_vs_map: Avoid test skipping by querying hugepage size at runtime

Currently, the size used in mmap() is statically defined, leading to
skipping of the test on a hugepage size other than 2 MB, since munmap()
won't free the hugepage for a size greater than 2 MB. Hence, query the
size at runtime.

Also, there is no reason why a hugepage allocation should fail, since we
are using a simple mmap() using MAP_HUGETLB; hence, instead of skipping
the test, make it fail.

Signed-off-by: Dev Jain <[email protected]>
---
tools/testing/selftests/mm/hugetlb_madv_vs_map.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
index d01e8d4901d0..8f122a0f0828 100644
--- a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
+++ b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
@@ -27,9 +27,9 @@
#include "vm_util.h"
#include "../kselftest.h"

-#define MMAP_SIZE (1 << 21)
#define INLOOP_ITER 100

+size_t mmap_size;
char *huge_ptr;

/* Touch the memory while it is being madvised() */
@@ -44,7 +44,7 @@ void *touch(void *unused)
void *madv(void *unused)
{
for (int i = 0; i < INLOOP_ITER; i++)
- madvise(huge_ptr, MMAP_SIZE, MADV_DONTNEED);
+ madvise(huge_ptr, mmap_size, MADV_DONTNEED);

return NULL;
}
@@ -59,7 +59,7 @@ void *map_extra(void *unused)
void *ptr;

for (int i = 0; i < INLOOP_ITER; i++) {
- ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
+ ptr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
-1, 0);

@@ -93,14 +93,16 @@ int main(void)
free_hugepages);
}

+ mmap_size = default_huge_page_size();
+
while (max--) {
- huge_ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
+ huge_ptr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
-1, 0);

if ((unsigned long)huge_ptr == -1) {
- ksft_exit_skip("Failed to allocated huge page\n");
- return KSFT_SKIP;
+ ksft_test_result_fail("Failed to allocate huge page\n");
+ return KSFT_FAIL;
}

pthread_create(&thread1, NULL, madv, NULL);
@@ -117,7 +119,7 @@ int main(void)
}

/* Unmap and restart */
- munmap(huge_ptr, MMAP_SIZE);
+ munmap(huge_ptr, mmap_size);
}

return KSFT_PASS;
--
2.39.2



2024-05-10 11:47:13

by Muhammad Usama Anjum

[permalink] [raw]
Subject: Re: [PATCH] selftests/mm: hugetlb_madv_vs_map: Avoid test skipping by querying hugepage size at runtime

On 5/9/24 2:54 PM, Dev Jain wrote:
> Currently, the size used in mmap() is statically defined, leading to
> skipping of the test on a hugepage size other than 2 MB, since munmap()
> won't free the hugepage for a size greater than 2 MB. Hence, query the
> size at runtime.
>
> Also, there is no reason why a hugepage allocation should fail, since we
> are using a simple mmap() using MAP_HUGETLB; hence, instead of skipping
> the test, make it fail.
>
> Signed-off-by: Dev Jain <[email protected]>
LGTM
Reviewed-by: Muhammad Usama Anjum <[email protected]>

> ---
> tools/testing/selftests/mm/hugetlb_madv_vs_map.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
> index d01e8d4901d0..8f122a0f0828 100644
> --- a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
> +++ b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
> @@ -27,9 +27,9 @@
> #include "vm_util.h"
> #include "../kselftest.h"
>
> -#define MMAP_SIZE (1 << 21)
> #define INLOOP_ITER 100
>
> +size_t mmap_size;
> char *huge_ptr;
>
> /* Touch the memory while it is being madvised() */
> @@ -44,7 +44,7 @@ void *touch(void *unused)
> void *madv(void *unused)
> {
> for (int i = 0; i < INLOOP_ITER; i++)
> - madvise(huge_ptr, MMAP_SIZE, MADV_DONTNEED);
> + madvise(huge_ptr, mmap_size, MADV_DONTNEED);
>
> return NULL;
> }
> @@ -59,7 +59,7 @@ void *map_extra(void *unused)
> void *ptr;
>
> for (int i = 0; i < INLOOP_ITER; i++) {
> - ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
> + ptr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
> MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
> -1, 0);
>
> @@ -93,14 +93,16 @@ int main(void)
> free_hugepages);
> }
>
> + mmap_size = default_huge_page_size();
> +
> while (max--) {
> - huge_ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
> + huge_ptr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
> MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
> -1, 0);
>
> if ((unsigned long)huge_ptr == -1) {
> - ksft_exit_skip("Failed to allocated huge page\n");
> - return KSFT_SKIP;
> + ksft_test_result_fail("Failed to allocate huge page\n");
> + return KSFT_FAIL;
> }
>
> pthread_create(&thread1, NULL, madv, NULL);
> @@ -117,7 +119,7 @@ int main(void)
> }
>
> /* Unmap and restart */
> - munmap(huge_ptr, MMAP_SIZE);
> + munmap(huge_ptr, mmap_size);
> }
>
> return KSFT_PASS;

--
BR,
Muhammad Usama Anjum

2024-05-27 13:49:23

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH] selftests/mm: hugetlb_madv_vs_map: Avoid test skipping by querying hugepage size at runtime



Am 09.05.24 um 11:54 schrieb Dev Jain:
> Currently, the size used in mmap() is statically defined, leading to
> skipping of the test on a hugepage size other than 2 MB, since munmap()
> won't free the hugepage for a size greater than 2 MB. Hence, query the
> size at runtime.
>
> Also, there is no reason why a hugepage allocation should fail, since we
> are using a simple mmap() using MAP_HUGETLB; hence, instead of skipping
> the test, make it fail.
>
> Signed-off-by: Dev Jain <[email protected]>
> ---


Likely it would make sense to rewrite that test to try with all available
hugetlb sizes (like cow.c does).

Acked-by: David Hildenbrand <[email protected]>


--
Thanks,

David / dhildenb